Fruit ripeness, seasonality, storage, safety, nutrition and practical signs of quality.
Unexpected red or pink flesh in a standard yellow banana is abnormal. Plant diseases, bruising or cold injury can discolor the interior; pronounced red staining is best discarded.
A light pink tint in coconut water can result from natural oxidation of phenolic compounds, but sour odor, fizz, slime, mold or damaged storage conditions point toward spoilage.
A sharply sour coconut is not normal. Fermentation, rancidity, shell damage, fizz, slime or mold are reasons to discard the water and meat rather than taste-test them.
Watermelon becomes mealy when cell structure breaks down from age, bruising or storage stress. Graininess alone is a quality issue; slime, sour odor, mold or widespread water-soaking mean discard.
A clean internal hollow can be a growth defect rather than spoilage. Cracks become concerning when surrounding flesh is slimy, moldy, fermented, leaking or broadly broken down.
Broad translucent or yellowish areas in a normally red watermelon often reflect tissue breakdown. Fresh smell and firmness matter; slime, sour odor, mold or leakage mean discard.
A very soft melon can simply be ripe, but watery collapse, slime, sour or alcoholic odor, mold, or prolonged warm storage point toward spoilage.
A melon with a clear alcoholic, vinegary, fizzy or yeasty taste has likely begun fermenting. Add slime, bubbles, leaking or mold and it should be discarded.
A very ripe mango can smell intense, but alcohol, vinegar, fizz, leaking tissue or widespread collapse point toward fermentation and deterioration rather than normal ripeness.
A brown pineapple center can be chilling-related black heart. A small firm area may be trimmed, but extensive wet browning, alcohol odor, mold or collapse warrants discarding the fruit.
A strong alcohol, beer or wine smell in pineapple points toward yeast fermentation, especially when the flesh is soft, fizzy, leaking or full of gas cavities.
Mangoes vary widely in natural fiber content. Strings are usually a cultivar and texture issue unless they come with slime, off odor, mold or extensive internal breakdown.